From: Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH 23/49] Add buffer head related helper functions
Date: Wed, 23 Jan 2008 14:06:48 -0800
Message-ID: <20080123140648.788fbc49.akpm@linux-foundation.org>
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Cc: linux-kernel@vger.kernel.org, aneesh.kumar@linux.vnet.ibm.com,
	"linux-ext4@vger.kernel.org" <linux-ext4@vger.kernel.org>
To: "Theodore Ts'o" <tytso@MIT.EDU>
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> On Mon, 21 Jan 2008 22:02:02 -0500 "Theodore Ts'o" <tytso@MIT.EDU> wrote:
> +}
> +EXPORT_SYMBOL(bh_uptodate_or_lock);
> +/**

Missing newline.

> + * bh_submit_read: Submit a locked buffer for reading
> + * @bh: struct buffer_head
> + *
> + * Returns a negative error
> + */
> +int bh_submit_read(struct buffer_head *bh)
> +{
> +	if (!buffer_locked(bh))
> +		lock_buffer(bh);
> +
> +	if (buffer_uptodate(bh))
> +		return 0;

Here it can lock the buffer then return zero

> +	get_bh(bh);
> +	bh->b_end_io = end_buffer_read_sync;
> +	submit_bh(READ, bh);
> +	wait_on_buffer(bh);
> +	if (buffer_uptodate(bh))
> +		return 0;

Here it will unlock the buffer and return zero.

This function is unusable when passed an unlocked buffer.

The return value should (always) be documented.

> +	return -EIO;
> +}
> +EXPORT_SYMBOL(bh_submit_read);
>  void __init buffer_init(void)

Missing newline.